pyranometry

Pyranometry is a scientific discipline focused on the measurement of solar radiation, specifically the power of electromagnetic radiation in the wavelength range of 300 to 3000 nanometers, which is the range of visible light and near-infrared radiation. This range is particularly relevant to the Earth's atmosphere and surface, as it encompasses the majority of the solar energy that reaches the Earth.

Pyranometers are the primary instruments used in pyranometry. These devices are designed to measure the solar irradiance, which is the power of solar radiation per unit area. Pyranometers typically consist of a thermopile or a photovoltaic cell that converts the absorbed solar radiation into an electrical signal, which is then measured and recorded.

Pyranometers can be classified based on their response characteristics. Class A pyranometers have a flat spectral response, meaning they measure all wavelengths of solar radiation equally. Class B pyranometers have a spectral response that is weighted to better match the response of the human eye, which is more sensitive to shorter wavelengths. Class C pyranometers have a spectral response that is weighted to better match the response of photovoltaic cells, which are more sensitive to longer wavelengths.

Pyranometry is used in a variety of applications, including meteorology, climatology, solar energy research, and agriculture. In meteorology, pyranometers are used to measure the solar radiation that reaches the Earth's surface, which is a key factor in determining weather patterns. In climatology, pyranometers are used to study long-term trends in solar radiation, which can provide insights into climate change. In solar energy research, pyranometers are used to measure the solar radiation that is available for conversion into electrical energy. In agriculture, pyranometers are used to study the effects of solar radiation on plant growth and development.